No abstract

The authors assessed the relationship between ventricular enlargement, cortical atrophy, regional brain glucose metabolism, and neuropsychologic performance in 10 alcoholics and 10 control subjects. Regional brain glucose metabolism was measured with fluorine-18 fluorodeoxyglucose (FDG) and positron emission tomography (PET). Cortical atrophy and ventricular size were evaluated quantitatively with magnetic resonance (MR) imaging. Alcoholics had decreased brain glucose metabolism and more cortical atrophy but did not have significantly greater ventricular size than did control subjects. The degree of ventricular enlargement and of cortical atrophy was associated with decreased metabolism predominantly in the frontal cortices and subcortical structures in both alcoholics and control subjects. There were no significant correlations between neuropsychologic performance and MR imaging structural changes, whereas various subtest scores were significantly correlated with frontal lobe metabolism. These data show that F-18 FDG PET is a sensitive technique for detecting early functional changes in the brain due to alcohol and/or aging before structural changes can be detected with MR imaging.

Much work has been done to assess individual differences in the ability to detect visceral activity, and most of this work has focused on heartbeat detection ability. This experiment attempted to determine if some underlying cortical event is associated with heartbeat detection ability, and further, to assess whether this cortical event is lateralized to the right hemisphere. Event-related cortical potentials, time-locked to the EKG R-wave and averaged over 400 samples, were studied at Fz, Cz, F7, and F8 in 12 subjects. The primary dependent measure of heartbeat detection accuracy was the standard deviation of the mean temporal latency, measured from peak EKG R-waves to the subjects' report of physical sensation of heartbeats. A significant relationship was found between the amplitudes of event related potentials (ERPs) in the right hemisphere and heartbeat detection accuracy.

This study was designed to determine how reliable and valid a Zone Comparison PDD test is when the same individuals are administered the same test on two different occasions. Seventy-two subjects were used in an analog mock crime study using a Zone Comparison test format. Thirty-six subjects were randomly assigned to "innocent" and thirty-six to "guilty" programmed conditions. In addition, each subject was assigned to either an "accurate", "inaccurate", or "no" feedback treatment group. The overall accuracy for Tests 1 and 2 was 67% and 61 % respectively. Excluding the inconclusive decisions, the accuracy for Test 1 was 94% and 88% for Test 2. Both Test results discriminated between guilty and innocent subjects. There were no significant differences: between the guilty subjects on Test 1 and Test 2; between the innocent subjects on Test I and Test 2; nor between the guilty and innocent subjects on Test 1. However, the accuracy for the guilty subjects on Test 2 was significantly different from the accuracy rate for innocent subjects on Test 2. There was no significant difference for the innocent subjects between Test 1 and Test 2, and no significant differences between feedback groups.